Trailer coupling



`Sept.8,1925. G. L. KNOX TRAILER COUPLING Filed -Aprl 9,l 1925 2 Sheets-Sheet 1 y' l.A

TRAILER COUPLING Filed April 9, 1923 2 Sheets-Sheet 2 ill/ly. .7'.

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Patented Sept. 8, 1925. i

UNITED STATES PATENT OFFICE.

GARNIER IMKNOX, OF. LOS ANGELES, CALIFORNIA, ASSIGNOB '10 UTILITY TRAILER I ANUFACTUBING COMPANY, A CORPORATION OF CALIFORNIA.'

TRAILER COUPLING.

Application led April 9, 19223. Serial No. 680,752.

To all whom 'it may concern. f. Beit known that I' Gamma L. KNOX, a citizen of the United tates residing 'at Los Angeles, in the county, of State of California, have invented new and useful Improvements in Trailer Couplings, of which the following'is a detailed specication.,

This invention relates to trailer couplings; and more particularly 4to couplings adapted to a two-wheeled trailer, .the vforward end of which'is supported by the towing vehicle. And a general object of the invention is the revision of a coupling mechanism that will provide for automatic elevation of the trailer onto the supporting vehicle, where it is supported on a4 strong and rigid structure. A,

Devices for elevating the forward end of a two-wheel trailer, and coupling that forward end to a truck or other towing vehicle, are well known in the art; but so far as Iam' aware such devices have usually been mounted on the vehicle'frame. trucks or tractors have either no frame at all or a frame of such type as to make it inconvenient to mount suc a device thereon; and in any situation, and particularly in those above stated, it has been found desirable, in some instances at least, to mount .the trailer carrying-devices `directly on the rear axle or rear axle housing, where the strains are. most directly transmitted to the rear su ortng wheels of the towing vehicle. y invention provides a peculiarly effective device 'adapted to be mounted in such a position; and in vthey following description I describe m device so mounted. Although specifically device' directly on the rear axle housing; and the device is specifically', here shown as designed for that mounting; yet, -in its broaderaspects, it will be .understood that the invention-is not necessarily limited to being specifically somounted'.

Thereare other objects and corresponding features of accomplishment of the invention,

1110s Angeles and Certain types of" prefer to vmount the including, in a device of this type, a means for automatically coupling the trailer .to

the towing vehicle; *but all the objects and features of accomplishment will be best 1111- derstood from the following detailed description of a specific form and arrangement that is illustrative Vof the invention, reference for this purpose being had to the accompanying drawin l F1g. 1 is a .longitudinal elevation, with parts in section, showing the trailer coupled tothe towing vehicle; Fig. 2 is a similar view showing the parts in theposition they assume when the trailer is uncoupled; Fig.

3 is a rear end elevation ofthe towing vehicle; Fig. ,4 is a Iplan of the rear end ofthe towing vehicle, ig.5 is a small side elevation 4showing the towing vvehicle and the trailer.A f

` In the drawings I show at 10 the .rear wheels of the towing vehicle and at 11 its rear axle housing with the 'differential cas.r v

ing 12 situated centrally of the axle housing, On the axle housing I mount two supporting members 13, one close to each wheel 10. y -These supqprtin members may be rigidly aiiixed to t e ax e housingwb clamps 14 as illustrated, and they preferably the axle housing and carry pivot pins 15 at their lowerends. v This location of the depend from i' pivot, at a point below the axle housing,v

gives the desired long radius ofv swinging action to the pivoted structure that is mounted o n members 13, and at the same time al# lows the 'upper 'bridge 4portion ofthe pivoted structure to lie closely to the axlehousing and differential case 12. This will also.

be understood fromthe drawings. This positioning of pivot pin 15'also, as willbe understood from consideration of the structure, applies the weight of the trailer tothe towing axle of that vehicle.A In this position, if the front end of the.towing vehicle rises, these pivot goints are vcorrespondingly moved forwar from a position under the yaxle and the weight ofthe trailer applied vehicle at a point below the rear.

i `crossl plates 21 isa bridge 22, preferably 'of such shape, as shown in Fig. 3,v as to have its central portion just clear thedifr'erential case 12, while its ends reach out and down tothe cross plates 21.

The bridge 22 carries at 1ts center and Aupper portion Aan upstanding pin 23; and

the bifurcated forward end 24 of trailer tongue`25 is adapted to engage with pin 23 in the manner shown in the drawlngs. The

vfront end of the trailer, when unconnected with the carriage vehicle, rests on a suitable support, as for instance, a small.wheel or wheels 26; and inthis position its tongue 25 will occupy about the relation to the pin l23 that is shown in Fig. 2. When it is desired to liftthe forward end of the trailer and connect itwith the towing vehicle, the parts are in the position shown in Fig. 2.. The towing vehicle is backed into the trailer the pin 23 being backed into the bifurcations 24; and when the pin strikes the rear end of this bifurcation, then the pivoted structuretpivoted at 15) is swung up to the position shown in Fig. 1. At this vtime the tongue 25 is resting on bridge 22, and so this upward swinging movement raises 'the ton e and raises the forward end of the to be moved u trai er, to the position shown in Fig. 1.

I also provide a means for automaticallycoupling the trailer to the towing vehicle; and although such means maybe provided in a variety of manners, I here illustrate one typical arrangement. For instance, I may secure a cross bar 30 between the lower parts of the two yokes 20, the middle part of this 'cross bar extending rearwardlyof the yokes, as illustrated in the drawings". When the pivoted parts turn up to the position'shown in Fig. 1, this cross bar moves from the position shown in Fig. 2 up to the position shown in Fig. l. At the same time that this motion takes place, the towing vehicle is mo-ving back onto the trailer, and therefore the cross bar 30 ismoving back as well as upwardly; and, as it moves back and upwardly, it comes up between two rollers or pins 32 mounted at the forward end of a draft bar 33 on the trailer. This draft bar 33 may be pivoted at 34 and normally held in a horizontal position by some suitable means, as by a spring 35. The spring may be of such shape that it will not allow the draft bar to drop beyond its horizontal position, but will allow the draft bar somewhatl to allow the forward pin or ro ler 32 to ride forwardly over the upper surface of cross bar 30 as that bar moves upwardly and rearwardly under the forward pin 32. Then, `when cross bar 3() reaches the position shown in Fig. 1, the forward pin 32 drops over the forward edge of the cross bar, and the trailer is' thus coupled to the towing vehicle.

A draft coupling of this general kind also has several other advantageous functions.

`For instance, it will be seen that the action of the draft bar 33 bearing down on cross bar 30, acts as a stop (and in this case, advantageously, as a resilient stop) to further forward swlngxing motion of bridge 22 and pin 23 about t e pivot 15. In other words, it `keeps this pivoted structure from moving on forward past the position shown 'in Fig. 1

DFurthermOre, the draft connection of course keeps the tongue 254 up against the 'pin 23; and therefore the draft connection vkeeps-*the pivoted swinging structure (the bridge 22, etc.) from tipping back tothe position of Fig. 2 and from lowering the trailer. `The pivoted structure cannot tip back, because in order to tip back the trailermust be shoved back, and the trailer cannot g be shoved back because of the draft connection at 30, 32; and this draft connection cannot be broken merely by tipping the pivoted parts back toward the position shown in Fig. 2, because any tendency of those pivoted parts to tip back "will immediately force the forward pin 32 back against bar 30 and thus stop further tipping of the structure. The only way in which the trailer can be disconnected from the towing vehicle is by lifting the pivoted draft bar 33, when the towing vehicle can then move forward, leaving the trailer behind and lowering it so that it rests on its forward support 26. f

Having described a preferred form of my invention, I claim 1. In a coupling device adapted to couple a trailer to a towing vehicle having a rear axle, a swinging trailer tongue supporting structure horizontally pivoted on the towing vehicle below the horizontal plane of the rear axle and adapted to swing toward and from a position iny vertical alinement with tween the towing vehicle and trailer, and means associated with the draft connection to limit movement of the swinging structure. v v

4. In a coupling device adapted to couple a trailer to a towing vehicle having a rear axle, a pair of pivot carrying members afiixed Ito the vehicle ustructure, a swinging structure pivoted on said members at points below the horizontal plane of the rear axle, and embodying a brldge adapted to carry the forward en d of the trailer, and means to limit the swinging movement of said structure. A

5. In a coupling device adapted to couple a trailer to a towing vehicle having a rear axle, a pair of pivot carrying members affixed to the vehicle structure, a' swinging structure pivoted on said members at a point under the rear axle and embodying a bridge adapted to carry the forward end ofthe trailer, and means to limit the swinging movement of said structure, said bridge being located above the pivots and above the rear axle and the structure swin g to and from a position in which the bridge is substantially vertically above the pivots.

6. A couphng device adapted to couple a trailer to a towing vehicle, embodying a pair of pivot carrying members axed to the' vehicle structure, a swinging structure pivoted on 'said members and embodying a bridge ada ted to carry thevforward end of the trai er, and means to limit the swinging movement of said structure, and draft connect-ion means between the trailer andvehicle in association with the swinging structure.

7. A coupling device adapted to couple a trailer to a towing vehicle, embodying a pair of pivot carrying members aixed to the vehicle structure, a -swinging structure piv-v oted on said members and embodying a bridge adapted to carry the forward end of the trailer, and means to limit the swinging movement of said structure, and draft conv(if) laxle housing, embod ing a pair of nection means between the trailer and ve- 4hicle in association with the swinging structure, said draft 'connection means also forming a movement limiting device for the swinging structure.

8. A coupling device adapted to couple a trailer to a towing vehiclelhaving a rear axle housing, embodying a pair of .pivot carrying members ai`n`xed to the axle hous near its opposite ends,fyokes pivoted to sai members and extending above the housing,

and a bridge mounted on and'between thev upper ends of the yokes.

v9. A coupling device adapted to couple a trailer. to a .towing vehicle' having a .rear

carrying members a ed to the axle ousf ing near its opposite ends, -yokes plvoted to said members andextending above thehous.v

.trailer ton e raisin and su ortin mein-A gu PE g no' ing, and a bridge mounted onand between the upper ends of the yokes, a guide pin carried on the bridge, the trailer having a tongue with a bifurcated end adapted-to rest on the bridge and encompass the pin.

10. A coupling ydevice adapted to couple a' trailer to a towing vehicle havin'g a rear axle housing, embodying a pair of pivot carrying members aiixed to the axle hous' ing near its opposite ends, yokes pivoted to said members and extending above the housing, and a bridge mounted on and between the upper end's of the yokes, a guide pin carried on the bridge, the trailer having a tongue vwith a bifurcated vend ada ted to rest on the bridge and encompass t e pin, the trailer having a draft bar with" downward projections, and a cross bar mounted on and between the two yokes and adapted to swing up to. a position between the draft bar projections.

11,'A coupling device adapted to couple a. trailer to a towing vehicle, comprising a swinging structure adapted. to swing on a horizontal axis on the towing vehicle and having a part adapted to support a trailer tongue, and draft means connecting the tow ing vehicle and trailer and limiting relative horizontal movement therebetween.

12. A coupling device adapted to couple a trailer to a towing vehicle, comprisingv 'a swinging structure adapted to. swin on a horizontal axis on the 'towing vehic e and having a part adapted to support a trailer tongue, and'draft means connecting the tow' ing vehicle and trailer and limiting relative horizontal movement therebetween, saiddraft' means including a memberthat is moved by swin movement of said swin ing structure into draft connection position. l

13.A coupling-device adaptedto` couple a trailer to a towing vehicle, comprising a ber movable with re tion to t e towing vehicle, and a separate draft connection between the vehicle and ,trailer and embodying a member that is moved into draft connection position by movement of the tongue supportlng member.

14. A'coupling device `adapted to couple a trailer to a towing vehicle, comprising al trailer tongue supportin member bearing upon the vehicle at a point .below its axle, and draft means connecting the vehicle and trailer and connectin to the vehicle'at 'a point not above its a e.

16. lA devlce for raising and supporting 130 a' trailer tongue 'on a `towing vehicle having a, rear' axle,v embodying a structure itongue is supported. y A

`-17. A device for raising and supporting a trailer tongue on a towing vehicle having' rear axle, embodying a structure svvingingn a horizontalA axis located .be`l

ingon a horizontal axis ,located below the rear axle and having a part extending above the pivot and engageable by the trailer tongue whereby the 'tongue is supported.

In Witness t have hereunto subscribed my name this 2 th day of. March 1923.

GARNER L. KNOX.

at I claim the foregoin -'I Y 

